The campaign says online privacy should be taught as an essential life skill “as natural as teaching a child to cross the road”.
In a survey of 1,000 UK parents of children aged four to 11, 35% said they believed their child would “share personal information in exchange for game tokens or rewards”.
The research found 22% of children had shared personal information such as health details with AI tools, while 24% have shared their real name or address online.
Eight and nine-year-olds are most at risk, according to the study.
Emily Keaney, ICO deputy commissioner, said many families had “never been shown how to talk to their children about online privacy”, and added that it required a “whole society approach”.
“Many parents are already talking to their children about harmful content or screen time, but privacy often gets overlooked,” Justine Roberts, founder of Mumsnet, said.
“As concerns grow about how children’s data is used online, families are looking for clear, practical guidance to help them start those conversations with confidence.”
The ICO’s survey of parents in February found 21% of parents had never spoken to their children about online privacy, while 38% discussed it less than once a month.
However, 90% of parents surveyed had discussed screen time with their children in the past month.
Online privacy includes children’s name, age and address as well as photos, browsing history, voice notes, and social media and gaming activity, the ICO said.
Dame Rachel de Souza, children’s commissioner for England, said: “Too often we are playing catch up, this is why it is important that parents feel confident having early, everyday conversations with children about the risks of being online and how to respond if something makes them uncomfortable.”